Posted by John Eickhof on Thursday, December 26, 2002 at 6:00PM :
In Reply to: new battery polarity problem in PW...mystery posted by George on Thursday, December 26, 2002 at 2:31PM :
If the ammeter is showing NO discharge or is slightly on the charge side when truck is running and lights are on maybe heater too..your charging system is working ok. If the regulator is solid state (70s and up Mopar) you will see hardly any charge motion on the ammeter except immediately after staerting! Earlier Mopars used a mechanical regulator (sometimes adjustable) with the alternator and the ammeter will tend to pulsate on charge when using accessories. Another sure fire way to make sure the ammeter is operating is to shut down the motor, then turn on lights, heater, etc, the ammeter should deflect to the discharge side more as each item is turned on! If in doubt then, start the truck with a DC voltmeter hooked up to the negative battery, and the alternator output, the output at 1000 rpm should be 14-18 volts! if it is, then check the output voltage of the regulator (the lead that goes to the positive battery terminal)
it should read from 13.4-14.2 volts at 1000 rpm when you have a load on the system. (lights, heater, etc) If it does, the system is fine!! If the voltage is 12.6 or less, the regulator is bad! Good luck!! Happy holidays
PS..only CHEBBY & Generous Motors used the internal regulator in primarily all of their systems. Ford & Mopar did more recently...